1. Field of the Disclosure
The present disclosure relates to a mobile terminal having an internal battery device including a secondary battery.
2. Description of Related Art
To date, mobile terminals called smart phones have rapidly become widespread. A mobile terminal uses a rechargeable battery (secondary battery) as a power source.
In general, in an apparatus in which the user is allowed to exchange a battery, the apparatus is provided to the user in a state of the battery removed from a body of the apparatus at the time of factory shipment of the product.
Japanese Unexamined Patent Application Publication No. 7-296856 describes a technique for preventing a very little current called a dark current from flowing in an internal circuit in a battery device when the battery device is left as it is without being connected to a load device in an apparatus, such as a video camera including a detachable battery, etc. Specifically, the battery device is internally provided with a means for detecting a connection with a load device or a charging device, and a switch for cutting off the battery from the internal circuit in a detected state of being unconnected with the load device or the charging device.
Also, in a state in which a battery device is attached to a body of an apparatus, such as a mobile terminal, etc., the battery device is electrically connected to a load device, and thus it is noted that even in a power-off state, a dark current flows. Accordingly, if the mobile terminal is left as it is without being charged for a certain period, the battery device becomes an over-discharged state, and it becomes necessary to charge the battery device at the time of turning on the power again. Also, there is a disadvantage in that if the over-discharged state takes long, the battery greatly deteriorates to become unavailable for use, etc.